| 摘要 |
<p>The present invention discloses a pulse mixing modulated - type switching power supply. It comprises: a direct current voltage input terminal, a transformer, a main switch tube, a resonant capacitor and a controlling circuit. The resonant capacitor is connected parallel with the primary side of the transformer. One terminal of the main switch tube is connected with one terminal of the primary side of the transformer, another terminal is connected with earth, its control terminal is connected with output signal of the controlling circuit. It characterized in that further comprises feedforward sampling resistor, one terminal of the resistor being connected with positive terminal of direct current voltage input terminal, another terminal being connected with triangular wave oscillator of pulse width modulator, as a part of clock oscillation charging signal. The present invention can ensure high reliability of the main switch tube.</p> |
